A “swim out” is a flat platform, bench or seat in or along the walls of a swimming pool that allows a swimmer in the deep end of the pool to stand or sit without getting out of the pool or going to the shallow end. Installation of a conventional swim out in an existing pool is very expensive and time consuming, since it requires that the pool be drained and one or more of its walls reconstructed. The present invention provides a quick and inexpensive retrofit swim out installation for existing in-ground and above-ground swimming pools.